This invention relates to a method of and an apparatus for charging the oven chambers of a battery of coke ovens with coal through charging holes in the oven roof.
When a coke oven is charged with coal, charging gases are generally evacuated through at least one collecting pipe which is arranged on at least one longitudinal side of the battery of coke ovens and which communicates with the oven chambers. This known method complies satisfactorily with clean-air requirements, but it is essential to maintain the suction pressure prevailing in the oven throughout the entire charging process by special measures. In one known charging method, so-called programme charging, the suction pressure prevailing inside the oven chambers is maintained by emptying only one feed hopper of a larry car travelling along the battery of coke ovens at a time, for which purpose only one charging hole at a time is exposed. This results in extremely long charging times which are unacceptable in modern high-speed coke oven plant. Other known larry cars are fitted with elaborate, quick-closing devices whose function is to carry over excess charging gases into adjacent semi-ready ovens. Devices of this kind are particularly necessary for charging ovens with only one gas collector pipe, or main. In this case, suction through the collecting pipe or main, is not intense enough to suck the charging gases through the dense "curtains" of inflowing coal which are inevitably formed in conventional charging processes.
All conventional charging processes without any external evacuation system on the larry car itself require large quantities of steam, which are injected into the take-off mains of the particular oven to be charged, for building up a sufficiently powerful internal suction in order to overcome the curtains of coal formed by the streams of coal flowing through the charging openings. It is especially in modern high-capacity ovens that one gas collector main is not sufficient for building up an adequate reduced pressure. In many cases, this makes it necessary to provide two collector mains with correspondingly increased costs.
In cases where preheated coal is introduced into the coke oven chambers, the problems described above are made more acute by the considerably greater accumulation of charging gases, because it is not possible with known systems to introduce the coal into the oven chambers in the absence of air on account of process difficulties.
An object of the present invention is to provide a method by which coke ovens can be charged with coal whilst, at the same time, charging gases are safely removed under suction through a collecting main.